Forum for Science, Industry and Business

Powering the next billion devices with Wi-Fi

19.11.2015

University of Washington engineers have developed a novel technology that uses a Wi-Fi router -- a source of ubiquitous but untapped energy in indoor environments -- to power devices.

The Power Over Wi-Fi (PoWiFi) system is one of the most innovative and game-changing technologies of the year, according to Popular Science, which included it in the magazine's annual "Best of What's New" awards announced Wednesday.

The UW team used ambient signals from this Wi-Fi router to power sensors in a low-resolution camera and other devices.

Credit: Dennis Wise/University of Washington

The technology attracted attention earlier this year when researchers published an online paper showing how they harvested energy from Wi-Fi signals to power a simple temperature sensor, a low-resolution grayscale camera and a charger for a Jawbone activity tracking bracelet.

The final paper will be presented next month at the Association for Computing Machinery's CoNEXT 2015 conference in Heidelberg, Germany, on emerging networking experiments and technologies.

"For the first time we've shown that you can use Wi-Fi devices to power the sensors in cameras and other devices," said lead author Vamsi Talla, a UW electrical engineering doctoral student. "We also made a system that can co-exist as a Wi-Fi router and a power source -- it doesn't degrade the quality of your Wi-Fi signals while it's powering devices."

PoWiFi could help enable development of the Internet of Things, where small computing sensors are embedded in everyday objects like cell phones, coffee makers, washing machines, air conditioners, mobile devices, allowing those devices to "talk" to each other. But one major challenge is how to energize those low-power sensors and actuators without needing to plug them into a power source as they become smaller and more numerous.

The team of UW computer science and electrical engineers found that the peak energy contained in untapped, ambient Wi-Fi signals often came close to meeting the operating requirements for some low-power devices. But because the signals are sent intermittently, energy "leaked" out of the system during silent periods.

The team fixed that problem by optimizing a router to send out superfluous "power packets" on Wi-Fi channels not currently in use -- essentially beefing up the Wi-Fi signal for power delivery -- without affecting the quality and speed of data transmission. The team also developed sensors that can be integrated in devices to harvest the power.

In their proof-of-concept experiments, the team demonstrated that the PoWiFi system could wirelessly power a grayscale, low-power Omnivision VGA camera from 17 feet away, allowing it to store enough energy to capture an image every 35 minutes.

It also re-charged the battery of a Jawbone Up24 wearable fitness tracker from zero to 41 percent in 2.5 hours.

The researchers also tested the PoWiFi system in six homes. Users typically didn't notice deterioration in web page loading or video streaming experiences, showing the technology could successfully deliver power via Wi-Fi in real-world conditions without degrading network performance.

Although initial experiments harvested relatively small amounts of power, the UW team believes there's opportunity for make the PoWiFi system more efficient and robust.

"In the future, PoWi-Fi could leverage technology power scaling to further improve the efficiency of the system to enable operation at larger distances and power numerous more sensors and applications," said co-author Shyam Gollakota, assistant professor of computer science and engineering.

###

The research is funded by the National Science Foundation, Qualcomm and the UW.

Die letzten 5 Focus-News des innovations-reports im Überblick:

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...